Files

Abstract

As spring and summer blooms of cyanobacteria are very common in many ponds, lakes and reservoirs of Bangladesh, the occurrence and abundance of dyanobacterial population and environmental parameters were examined in lsha Khan lake of Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh from February to April to see how environmental factors affect the spring bloom of cyanobacteria. Sampling was done bi-weekly during the non-bloom period but daily from the conspicuous bloom to heavy bloom. During the study period 5 species of cyanobacteria namely, Microcystis aeruginosa Katz., Microcystis wesenbergii Kom., Microcystis bottys Teli., Microcystis viridis (A. Br.) Lemm. and Anabaena circinalis Rabenh. were identified. A heavy bloom of cyanobacteria occurred in the lake at the end of March. The bloom comprised mainly M. aeruginosa followed by M. wesenbergii. At the peak bloom period, the highest cell density of M. aeruginosa was 1550 x 103 cells/m1 which comprised 97.45% among the cyanobacteria and 96.84% of the total phytqplankton population. From the findings of the study, it can be concluded that the causes of the spring" bloom of cyanobacteria in the lake were accumulating nutrients being enriched before the bloom period that was further increased by the rainwater run-off entered into the lake followed by calm, warm and comparatively windless days.

Details

PDF

Statistics

from
to
Export
Download Full History